Summary: GENETICS OF LATERAL PLATE AND GILLRAKER
PHENOTYPES IN A RAPIDLY EVOLVING POPULATION
OF THREESPINE STICKLEBACK
by
WINDSOR E. AGUIRRE1,2)
, PATRICIA K. DOHERTY and MICHAEL A. BELL
(Department of Ecology and Evolution, State University of New York, Stony Brook,
New York 11794-5245, USA)
(Acc. 14-IX-2004)
Summary
Twenty-seven crosses were used to study the genetics of rapidly evolving traits in a recently
founded population of threespine stickleback in Loberg Lake, Alaska. Lateral plate morph
segregation ratios were inconsistent with all published models of lateral plate morph genetics
except Avise's (1976) general two-locus model. Incompatibility of the results of our plate
morph crosses with those of most previous studies suggests that the genetic architecture un-
derlying lateral plate morphs differs among populations or is more complex than presently
recognized. Segregation ratios for lateral plate morphs indicate that consistently low frequen-
cies of partial morphs observed in the Loberg Lake population at least partly reflect genetic
architecture. Gillraker number and probably low morph lateral plate number are highly heri-
table and correlated with each other. Lateral plate asymmetry was high but not significantly